(10 pts) Let f(x, y) = e2x+3y-5. (a) (2 pts) Find Vf(4, -1). (b) (4 pts) Find the directional derivative of f(x, y) at (4, -1) in the direction of the vector V = (5, -2). (c) (2 pts) Find the direction in which f(x, y) decreases most rapidly at (4, -1). (d) (2 pts) Find the minimum value of the directional derivative of f(x, y) at (4, -1)